HONG KONG (Reuters) - Anheuser-Busch InBev has enlisted Citigroup and Bank of America Merrill Lynch (BAML) to the team of banks working on the sale of its Asia-Pacific business, three people with direct knowledge of the matter told Reuters.

They join Morgan Stanley and JP Morgan, both of which are the sponsors, or leads, for the planned Hong Kong initial public offering (IPO) which could raise up to $5 billion for the heavily indebted Belgium-based brewer, the sources said.

The world's biggest brewer, whose brands include Budweiser, Corona and Stella Artois, said it had always looked at opportunities to optimize its business.

"There is, however, no decision as to whether we might undertake an IPO or any other potential transaction relating to our Asia Pacific business," AB InBev said, adding it was committed to being a long-term investor in the region.

Citi and BAML declined to comment.

AB InBev's Asia-Pacific region, whose main markets are China and Australia, last year made up 18 percent of group volume and 14 percent of underlying operating profit, which in turn rose 13 percent to $3.1 billion.

The sources said AB InBev aims to spin-off the business to reduce its net debt, which stood at $102.5 billion at the end of December, a figure inflated by its late 2016 purchase of nearest rival SABMiller for around $100 billion.

AB InBev wants to bring its net debt/EBITDA (earnings before interest, tax, depreciation and amortization) ratio to around two times from a multiple of 4.6 at the end of last year. With that goal, it has halved its proposed dividend and said payouts will only grow slowly.

While AB InBev's shares have risen 19 percent since reporting forecast-beating earnings in February, the brewer is battling to reverse a longer share price decline. Over the past two years, its shares have fallen 24 percent, in contrast to rivals Heineken and Carlsberg, which have gained 15 and 28 percent respectively.

The IPO would not be the first time AB InBev has sold Asia-Pacific assets to reduce debt. After InBev bought Anheuser-Busch in 2008, AB InBev sold South Korean unit Oriental Brewery to private equity firm KKR - only to buy it back in 2014.

The IPO is slated for the second half of the year and the brewer expects to file with the Hong Kong stock exchange in the first half, the people said. One of the people said the filing would happen either later this month or early May.

At $5 billion, the IPO could be the largest in Hong Kong this year, where the flood of companies looking to go public has slowed to a trickle.

Companies have raised $2.9 billion through Hong Kong listings so far this year, lagging the $6.4 billion raised on New York's Nasdaq, showed Refinitiv data as of Friday.

Hong Kong topped all other exchanges globally last year with stock market listings raising $36.3 billion. This year, however, is widely expected to be slower due to thinning numbers of Chinese companies looking to go public, particularly in tech.